The term "mortification of the flesh" comes from the Book of Romans in the Christian Bible: "For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body you will live."[5] The same idea is seen in the following verses: "Put to death what is earthly in you: fornication, impurity, passion, evil desire, and covetousness, which is idolatry";[6] "And those who belong to Christ Jesus have crucified the flesh with its passions and desires".[7]

According to Christian exegesis, "deeds of the body" and "what is earthly", refer to the "wounded nature" of man or his concupiscence (evil inclinations due to forming part of the Fall of Man); humanity suffers the consequences of the original sin. The Apostle Paul, who authored Romans, expected believers to "put to death" the deeds of the flesh.[citation needed]

In its simplest form, mortification of the flesh can mean merely denying oneself certain pleasures, such as permanently or temporarily abstaining (i.e. fasting), from food, alcoholic beverages, sexual relations, or an area of life that makes the person's spiritual life more difficult or burdensome. It can also be practiced by choosing a simple or even impoverished lifestyle; this is often one reason many monks of various religions take vows of poverty. Among votarists, traditional forms of physical mortification are the cilice and hair-shirts. In some of its more severe forms, it can mean using a discipline to flagellate oneself.

In Christianity, the Rev. Michael Geisler, a Catholic priest of the Opus Dei Prelature in St. Louis, wrote two articles explaining the theological purpose behind corporal mortification. "Self-denial helps a person overcome both psychological and physical weakness, gives him energy, helps him grow in virtue and ultimately leads to salvation. It conquers the insidious demons of softness, pessimism and lukewarm faith that dominate the lives of so many today" (Crisis magazine July/August 2005). Some theologians explain that the redemptive value of pain makes pain lovable in its effects, even though by itself it is not. Pain is temporal and limited, thus to undergo it is worthwhile to gain the real benefits. For those with this viewpoint, pain is seen as a means to an end. Thus, a modern Catholic saint, Josemaria Escriva said, while consoling a dying woman who was suffering in a hospital, "Blessed be pain! Glorified be pain! Sanctified be pain!"[8] The root of the modern-day perplexity over mortification, according to some theologians, is the "practical denial of God," a refusal to accept any but material realities.

The early Christian evangelist and church-planter Paul wrote, "I chastise my body and bring it into subjection: lest perhaps when I have preached to others I myself should be castaway" (1 Cor 9:27); "In my flesh I complete what is lacking in Christ's afflictions, for the sake of his body, that is the Church." (Col 1:24).

Through the centuries, some Christians have practiced voluntary penances as a way of imitating Jesus who, according to the New Testament, voluntarily accepted the sufferings of his passion and death on the cross at Calvary in order to redeem humankind.[citation needed] Some Christians note that the cross carried by Jesus is the crossbar or patibulum, a rough tree trunk, which probably weighed between 80 and 110 pounds.[citation needed]

Christ also fasted for 40 days and 40 nights, an example of submission to the first person of the Trinity, God the Father, and as a way of preparing for ministry. The early Christians mortified the flesh through martyrdom and through what has been called "confession of the faith": accepting torture in a joyful way. As Christians experienced persecution, they often embraced their fate of suffering due to their love for Christ and the transformation they said they experienced from following him; these individuals became martyrs of the Christian faith.[9][10]Saint Jerome, a Western church father and biblical scholar who translated the Bible into Latin (the Vulgate), was famous for his severe penances in the desert.

Some canonized Catholic saints and founders of Roman Catholic religious organizations practiced mortification in order to imitate Christ.[citation needed] Another way of self-denial that developed quickly in the early centuries was celibacy, which the Roman Catholic tradition interprets as forsaking sex and procreation for a superior chastity and higher supernatural ends.

For they [our teachers] have always taught concerning the cross that it behooves Christians to bear afflictions. This is the true, earnest, and unfeigned mortification, to wit, to be exercised with divers afflictions, and to be crucified with Christ. Moreover, they teach that every Christian ought to train and subdue himself with bodily restraints, or bodily exercises and labors that neither satiety nor slothfulness tempt him to sin, but not that we may merit grace or make satisfaction for sins by such exercises. And such external discipline ought to be urged at all times, not only on a few and set days. So Christ commands, Luke 21:34: Take heed lest your hearts be overcharged with surfeiting; also Matt. 17:21: This kind goeth not out but by prayer and fasting. Paul also says, 1 Cor. 9:27: I keep under my body and bring it into subjection. Here he clearly shows that he was keeping under his body, not to merit forgiveness of sins by that discipline, but to have his body in subjection and fitted for spiritual things, and for the discharge of duty according to his calling.[11]

In the Lutheran tradition, mortification of the flesh is not done in order to earn merit, but instead to "keep the body in a condition such that it does not hinder one from doing what one has been commanded to do, according to one's calling (Latin: juxta vocationem suam)."[12] In The Ninety-Five Theses, Martin Luther stated that "inner repentance is worthless unless it produces various outward mortification of the flesh."[13]

Samuel Wesley, Sr. examined the writings of Thomas à Kempis on the mortification of the flesh and concluded that "mortification is still an indispensable Christian duty."[14] His son, John Wesley, the evangelical Christian progenitor of the Methodist Church continued "to hold à Kempis in high regard".[14] As such, he likewise wrote that "efforts to manifest true faith would be 'quickened' by self mortification and entire obedience".[15] Moreover, he "spoke approvingly of 'voluntary instances of mortification' in his journals".[15] Methodist circuit riders were known for practicing the spiritual discipline of mortifying the flesh as they "arose well before dawn for solitary prayer; they remained on their knees without food or drink or physical comforts sometimes for hours on end".[16]John Cennick, the first Methodist itinerant preacher, prayed nine times a day, fasted and "fancying dry bread too great an indulgence for so great a sinner as himself, he began to feed on potatoes, acorns, crabs, and grass".[17] The Methodist evangelist John Wesley Childs was known for "limiting what he would eat" and choosing "to walk beside his horse rather than to ride in order to demonstrate his willingness to suffer for his calling and to try[ing] to heighten his religious experience through subjecting himself to trials."[18] The Wesleyan Methodist Magazine published a statement written by Matthew Henry for Christian believers:[19]

By using yourselves to consideration, you will come to be aware of the snares that your spiritual enemies lay for you, of the snake under the green grass, and will not be imposed upon so easily as many are by the wiles of Satan; and by habituating yourselves to self-denial and mortification of the flesh, and a holy contempt of this world, you will wrest the most dangerous weapons of the hand of the strong man armed, and will take from him that part of his armour most trusted, for it is by the world and the flesh that he mostly fights against us: nay, and this sober-mindedness will put you the whole armour of God, that you may be able to stand in the evil day; and so to resist the devil, that he may flee from you.[19]

According to other Evangelical Christian commentators, using Paul's writings and other passages from the New Testament to justify the practise of mortification of the flesh is a complete misinterpretation. In the verses leading up to Col 1:24 Paul holds a very high view of Christ's redeeming work. "He understands this redemptive work to be finished, completed, and perfected. Nothing remains to be done, and the suffering of Christ's followers does not put the finishing touches on the triumph of Calvary. Paul does not believe that suffering has any atoning benefit for himself or for others. It does, however, 'serve to increase Paul's living knowledge of Christ.'"[21] This suffering Paul refers to comes as one takes on the commission to share the gospel. Persecution and suffering such as that experienced by Christ will follow and Christians should see this suffering as a divine necessity. In chapter 9 "Paul compares the evangelistic lifestyle of believers to athletes who sacrifice normal pursuits for the sake of strict training and a competitive edge".[22] In the Corinth church there were grey areas of lifestyle and behaviors (see 1 Cor 8) not specifically covered by the Mosaic law, and Paul was encouraging them to discipline themselves to abstain from those behaviors and practices for the sake of winning others to Christ. Mortification of the flesh being self-flagellation is something that is read into the text and an errant interpretation of it.

Some indigenous cultures' shamans believe that endurance of pain or denial of appetites serves to increase spiritual power. In many indigenous cultures, painful rites are used to mark sexual maturity, marriage, procreation, or other major life stages. In Africa and Australia, indigenous people sometimes use genital mutilation on boys and girls that is intentionally painful, including circumcision, subincision, clitoridectomy, piercing, or infibulation. In some Native American tribes enduring scarification or the bites of ants are common rituals to mark a boy's transition to adulthood. Human rights organizations in several areas of the world have protested some of these methods, which can be forced upon the participants, although some are voluntary and are a source of pride and status.[23]

Shamans often use painful rites and self-denial such as fasting or celibacy to attain transformation, or to commune with spirits.[24]

It has been speculated that extreme practices of mortification of the flesh may be used to obtain an altered state of consciousness to achieve spiritual experiences or visions. In modern times, members of the Church of Body Modification believe that by manipulating and modifying their bodies (by painful processes) they can strengthen the bond between their bodies and spirits, and become more spiritually aware. This group uses rites of passage from many traditions including Hinduism, Buddhism and shamanism, to seek their aims.[25]

In some contexts, modern practices of body modification and plastic surgery overlap with mortification. Often, secular people will undergo painful experiences in order to become more self-aware, to take control of their bodies or "own" them more fully, to bond with a group that is spiritual in its aims, or to overcome the body's limitations in ways that do not refer to any higher power. Many times these rites are intended to empower the participant, rather than humble them. This represents a very different aim than many traditional mortifications.[26]

Roland Loomis re-creates Sun dance ceremonies and suspensions for those who believe these painful procedures expand their consciousness.[27] Musafar explains his use of these rites as a way to awaken the spirit to the body's limits, and put it in control of them. Others who have used these experiences to transcend physical limitations report a feeling of mastery over their physical circumstance, along with a widened perspective.[28]

^Scheckel, Roger J. (2006). "Seeking Sanctification Through the Practice of Mortification". Marian Catechist Apostolate. Retrieved 14 June 2016. Saint Paul sets forth in the above two passages the fundamental reason why we are in need of mortification. The Christian must continually seek to crucify and put to death that dimension of our self that remains under the influence of the fallen state of the First Adam into which we are conceived and born. After our baptism, the imputed sin of our First Parents is washed from our life, however a residue or stain of the Original Sin remains with us, what is known as concupiscence. The effects of this residue or stain are experienced primarily in our will, tending in the direction of a love of self rather than a love of God. This is what is meant by a “disordered will.” This disorder can be expressed through our external senses as well as the operations of our soul, e.g., the imagination, memory and intellect. Mortification seeks to address these manifestations of the “disordered will.”

^Wilkins, John; Nadeau, Robin (17 August 2015). A Companion to Food in the Ancient World. John Wiley & Sons. p. 83. ISBN9781405179409. In this period Clement of Alexandria, St Jerome, and Tertullian make the mortification of the flesh by fasting and abstinence as a way to holiness.

^Onu, Godsword G. (2 February 2015). The Anointing and Power of the Holy Spirit. Osmora Incorporated. p. 25. ISBN9782765908661. The Holy Spirit frees the believers from sin and death. To this end the Word declares, "There is therefore now no condemnation to those who are in Christ Jesus, who do not walk according to the flesh, but according to the Spirit. For the Las of the Spirit of Life in Christ Jesus has made me free from the law of sin and death" (Rom. 8:1-2). The Holy Ghost is the Agent of the mortification of the sins of the flesh (Rom. 8:12-13).

^Pierson, Paul Everett (2009). The Dynamics of Christian Mission: History Through a Missiological Perspective. WCIU Press. p. 45. ISBN9780865850064. A third factor Christians brought was their belief in Jesus' resurrection, and the certainty of their own eternal life. That made them willing to die for their faith. There are many stories of martyrs who, before death, won to the faith their persecutors or those that watched them die.

^Germain, Blaine St. (7 September 2011). Generation Transformed. Lucid Books. p. 58. ISBN9781935909293. In 302 A.D. Emperor Diocletian issued the first of many edicts to persecute Christians. ... When others began to see the Christians' devotion and willingness to die for their beiefs, they began to question their own lives. Even though there were an estimated 20,000 people killed in the persecution, Christianity grew. ... These men were willing to die to spread the message of Jesus. They experienced transformation and wanted others to do the same.

^Neve, Juergen Ludwig (1914). The Augsburg Confession: A Brief Review of Its History and an Interpretation of Its Doctrinal Articles, with Introductory Discussions on Confessional Questions. Lutheran Publication Society. p. 150.|access-date= requires |url= (help)

^Weber, Max (2002). The Protestant Ethic and the "spirit" of Capitalism and Other Writings. Penguin Books. p. 54. ISBN9780140439212.

^ abTorpy, Arthur Alan (26 October 2009). The Prevenient Piety of Samuel Wesley, Sr. Scarecrow Press. p. 104. ISBN9780810870826. Samuel weighed the pros and cons of Thomas à Kempis on the mortification of the flesh with Samuel taking a moderate position between two extremes. As for T. Kempsis, all the world are apt to strain o' one side or t'other. And 'tis no wonder if contemplative men...when they observed how mad the bulk of the world was for sensual pleasures, should run the matter too far o' the contrary extreme, and attempt to persuade us to have no senses at all ...But for all that, mortification is still an indispensable Christian duty." John, in his later years, would continue to hold à Kempis in high regard, recommending him to Sammie Wesley, Charles's son, for edification and hoped for evangelical conversion.

^Bratt, James D. (2012). By the Vision of Another World: Worship in American History. Wm. B. Eerdmans Publishing. p. 44. ISBN9780802867100. Methodist preachers, in particular, may have been tempted to take the elevation of the spirit and concomitant mortification of the body to extremes. Early circuit riders often arose well before dawn for solitary prayer; they remained on their knees without food or drink or physical comforts sometimes for hours on end.

^Rubin, Julius H. (1994). Religious Melancholy and Protestant Experience in America. Oxford University Press. p. 84. ISBN9780195083019. Ascetic disciplines in both Catholicism and Protestantism were a system of rules of conduct to control the flesh by starvation and renunciation." John Cennick, the first Methodist lay preacher, exemplifies the fact that Protestant ascetics were required to adopt monastic regimens of the body in their everyday lives. "He fasted long and often, and prayed nine times a day. Fancying dry bread too great an indulgence for so great a sinner as himself, he began to feed on potatoes, acorns, crabs, and grass; and often wished that he could live on roots and herbs.

^Bratt, James D. (2012). By the Vision of Another World: Worship in American History. Wm. B. Eerdmans Publishing. p. 44. ISBN9780802867100.